Tidal stream energy is gaining momentum globally as a stable and highly predictable renewable source. Yet in many regions — including Singapore — there is still limited clarity on how much energy can be practically extracted, where the best sites are, and what meaningful contributions tidal power could make to national electricity supply and emissions reduction.
A new study published in Energy Conversion and Management (Volume 348, 2026) led by Associate Professor Low Ying Min from the Department of Civil and Environmental Engineering details the use of turbine-scale ocean simulations to map where Singapore’s tidal currents are strongest, estimate realistic electricity production under installation constraints, and translate that output into potential reductions in CO2 emissions.
Why tidal stream energy — and why Singapore
Unlike wind and solar, tidal currents are highly predictable and follow well-known cycles. For Singapore, where wind and wave resources are limited by geography, tidal stream energy is one of the few marine renewables with credible local potential — especially in narrow straits where flow accelerates around islands and through channels.
But turning that promise into numbers requires more than a coarse map. Tidal currents can change sharply over short distances due to seabed shape, shoreline geometry, and coastal structures, so assessments based on low-resolution data can miss or misrepresent key hotspots.
Building a turbine-scale simulation of Singapore’s tides
To address this, the researchers built a detailed FVCOM (Finite-Volume Community Ocean Model) hydrodynamic simulation. The model uses an unstructured grid that allows higher resolution in complex coastal areas. Near key tidal channels around Singapore, the grid resolution is refined to about 50m, consistent with international guidance for layout-design-level tidal studies.
Critically, the model is driven by 13 tidal constituents (including major semi-diurnal and diurnal components) and incorporates up-to-date shoreline information and high-resolution seabed depth data, including 10m depth data. This matters in a rapidly changing coastal environment where reclamation and engineered shorelines can alter flow paths.
Because tidal resource estimates depend on the accuracy of the underlying current fields, the team validated the model against multiple independent datasets. For Singapore waters, they compared simulated water levels against the Maritime and Port Authority of Singapore (MPA) tide-gauge records over 1–15 June 2023 at 10 stations: Pulau Bukom, Changi, Pulau Ubin, Raffles Lighthouse, Sultan Shoal, Sembawang, Tanah Merah, Tanjong Pagar, West Coast, and West Tuas.
Overall, the validation indicates that the model predicts tidal water levels with high accuracy and represents tidal currents well enough for resource assessment, while also highlighting known hard-to-model areas near complex island/coastal-structure settings.
Where the energy is: channels, islands, and the Singapore Strait
With the validated simulation, the researchers mapped mean and peak tidal currents and computed tidal kinetic power density.
To go beyond “2D maps”, the team also examined four cross-strait profiles to understand how speed and energy vary with depth — important because turbine feasibility depends not only on current speed but also on water depth.
The team selected eight representative hotspot sites. They then tested performance across nine tidal current turbine (TCT) designs, spanning small to large rotors and different cut-in/rated speeds.
This series of side-by-side comparisons revealed a practical trade-off: large turbines can produce high energy per device, but they are constrained by depth and siting; smaller, low-cut-in-speed turbines can be deployed across more of Singapore’s feasible areas and may deliver higher aggregate output at scale. Prof Low confirmed, “I believe it is more practical to deploy a combination of different turbines, since tidal stream characteristics and water depths vary across locations.
A national-scale estimate under real installation constraints
The researchers proposed a deployment framework that:
- Restricts installations to Singapore’s Exclusive Economic Zone (EEZ) — waters where Singapore has rights to marine resources — while excluding marine protected areas.
- Sets minimum water-depth requirements based on turbine size and safe clearances.
- Uses spacing rules between turbines to reflect realistic “farm” layouts.
- Estimates total electricity by adding up annual energy production from all suitable locations.
- Converts this electricity into estimated CO2 reductions using Singapore’s grid carbon intensity (and tidal energy’s low life-cycle emissions).
The result: The estimated output reaches 12.85 Terawatt-hour (TWh) per year, which the authors note is about 22% of Singapore’s 2023 electricity demand, with a corresponding reduction of roughly 6.03 million tonnes of CO2 annually under the paper’s accounting approach.
Other turbines also showed substantial potential (~10–11 TWh/year in the best cases), reinforcing that the “best” device is not just about maximum power per unit, but also about fit with depth, spacing, and the speed distribution of Singapore’s tides.
Limitations and uncertainties
The paper is explicit about uncertainties and where future work is needed:
- Current-speed uncertainty matters enormously because power is proportional to the cube of speed. Even modest speed errors can amplify into large power uncertainty.
- The national estimates assume undisturbed flow at each turbine location and do not fully model array wake interactions and far-field hydrodynamic feedback, which can reduce downstream speeds and farm efficiency.
- Carbon reduction estimates use literature-average life-cycle emissions for tidal stream energy; Singapore-specific project supply chains and fabrication pathways could shift that number.
In other words, the study should be interpreted as a high-resolution, engineering-grounded upper-bound estimate that sharpens where the promising zones are and what deployment at scale might look like — rather than as a final bankable yield for a specific project.
Why it matters for Singapore and NUS
For Singapore’s energy transition, the work provides a validated, turbine-relevant resource picture tied directly to practical turbine choices and siting constraints, and linked to electricity-system and decarbonisation implications. Prof Low added, “Some areas around Singapore, such as near Bukom Island and Semakau Island, show promising potential for tidal stream energy, and could be suitable for supplying electricity to nearby local islands, subject to further site screening and maritime constraints.”
For the NUS community, it also demonstrates a transferable workflow — namely, high-resolution coastal modelling, multi-source validation, turbine performance coupling, and constrained spatial deployment — that can be applied to other coastal regions where resource predictability is attractive, but seabed topography and siting limitations complicate development. Assoc Prof Low elaborated, “As Singapore actively pursues strategies for sustainable maritime energy, this work seeks to determine whether tidal stream energy could be integrated into the nation’s future energy mix. We hope this research will serve as a scientific basis and a practical reference for stakeholders and investors interested in the development and deployment of tidal energy systems in Singapore and similar maritime contexts.”
To underscore how this research adds practical decision-making value beyond estimating resource size, Prof Lee Poh Seng, Head of the Department of Mechanical Engineering, noted: “Studies like this are valuable because they move the discussion on tidal energy beyond broad resource claims toward site-specific engineering evidence. In Singapore’s context, the real significance is not the headline percentage alone, but the clearer picture of where the more promising zones may be, which turbine and siting trade-offs matter most, and where the major uncertainties still lie. The 22% figure should be understood as modelled technical potential under stated assumptions, not as an immediately deployable national supply outcome. The real contribution of the work is that it strengthens the evidence base for deciding whether and where tidal-stream energy could play a practical role in Singapore’s broader low-carbon energy mix.”
